The objectives of this project are to fully characterize pertussigen, a substance from Bordetella pertussis, and to study its role in the biological activities of pertussis vaccine. The ultimate goals are to discover the mechanisms of action by which this and other substances from B. pertussis produce various changes in mice and to develop a pertussis vaccine free of undesirable side reactions. The enhanced production of the IgE class of antibodies by pertussigen is of great interest to us. This adjuvant action is important because IgE is responsible for many allergic sensitivities in man and animals. To solve these problems, one of our prime concerns has been to obtain biologically active antigens of B. pertussis in pure form. When this is accomplished, studies on the mode of action of these substances will be greatly facilitated. Another employing sensitive and reliable methods such as the enzyme-linked immunosorbent assay (ELISA). This test has already been adapted for measuring fimbrial hemagglutinin and its corresponding antibody.